mirror of https://github.com/mautrix/go.git
79 lines
3.1 KiB
Go
79 lines
3.1 KiB
Go
// Copyright (c) 2020 Tulir Asokan
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//
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// This Source Code Form is subject to the terms of the Mozilla Public
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// License, v. 2.0. If a copy of the MPL was not distributed with this
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// file, You can obtain one at http://mozilla.org/MPL/2.0/.
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package ssss
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import (
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"errors"
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"fmt"
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"reflect"
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"maunium.net/go/mautrix/event"
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)
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var (
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ErrNoDefaultKeyID = errors.New("could not find default key ID")
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ErrNoDefaultKeyAccountDataEvent = fmt.Errorf("%w: no %s event in account data", ErrNoDefaultKeyID, event.AccountDataSecretStorageDefaultKey.Type)
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ErrNoKeyFieldInAccountDataEvent = fmt.Errorf("%w: missing key field in account data event", ErrNoDefaultKeyID)
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ErrNoKeyGiven = errors.New("must provide at least one key to encrypt for")
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ErrNotEncryptedForKey = errors.New("data is not encrypted for given key ID")
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ErrKeyDataMACMismatch = errors.New("key data MAC mismatch")
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ErrNoPassphrase = errors.New("no passphrase data has been set for the default key")
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ErrUnsupportedPassphraseAlgorithm = errors.New("unsupported passphrase KDF algorithm")
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ErrIncorrectSSSSKey = errors.New("incorrect SSSS key")
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ErrInvalidRecoveryKey = errors.New("invalid recovery key")
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)
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// Algorithm is the identifier for an SSSS encryption algorithm.
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type Algorithm string
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const (
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// AlgorithmAESHMACSHA2 is the current main algorithm.
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AlgorithmAESHMACSHA2 Algorithm = "m.secret_storage.v1.aes-hmac-sha2"
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// AlgorithmCurve25519AESSHA2 is the old algorithm
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AlgorithmCurve25519AESSHA2 Algorithm = "m.secret_storage.v1.curve25519-aes-sha2"
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)
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// PassphraseAlgorithm is the identifier for an algorithm used to derive a key from a passphrase for SSSS.
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type PassphraseAlgorithm string
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const (
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// PassphraseAlgorithmPBKDF2 is the current main algorithm
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PassphraseAlgorithmPBKDF2 PassphraseAlgorithm = "m.pbkdf2"
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)
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type EncryptedKeyData struct {
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// Note: as per https://spec.matrix.org/v1.9/client-server-api/#msecret_storagev1aes-hmac-sha2-1,
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// these fields are "maybe padded" base64, so both unpadded and padded values must be supported.
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Ciphertext string `json:"ciphertext"`
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IV string `json:"iv"`
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MAC string `json:"mac"`
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}
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type EncryptedAccountDataEventContent struct {
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Encrypted map[string]EncryptedKeyData `json:"encrypted"`
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}
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func (ed *EncryptedAccountDataEventContent) Decrypt(eventType string, key *Key) ([]byte, error) {
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keyEncData, ok := ed.Encrypted[key.ID]
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if !ok {
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return nil, ErrNotEncryptedForKey
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}
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return key.Decrypt(eventType, keyEncData)
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}
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func init() {
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encryptedContent := reflect.TypeOf(&EncryptedAccountDataEventContent{})
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event.TypeMap[event.AccountDataCrossSigningMaster] = encryptedContent
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event.TypeMap[event.AccountDataCrossSigningSelf] = encryptedContent
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event.TypeMap[event.AccountDataCrossSigningUser] = encryptedContent
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event.TypeMap[event.AccountDataSecretStorageDefaultKey] = reflect.TypeOf(&DefaultSecretStorageKeyContent{})
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event.TypeMap[event.AccountDataSecretStorageKey] = reflect.TypeOf(&KeyMetadata{})
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event.TypeMap[event.AccountDataMegolmBackupKey] = reflect.TypeOf(&EncryptedAccountDataEventContent{})
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}
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